Troffer light fixture retrofit systems and methods

ABSTRACT

A retrofitting kit for retrofitting an existing troffer light fixture having a troffer housing includes an adaptor bracket and a door assembly. The adaptor bracket is configured to rest on a T-bar of a ceiling system, and further configured to be located between the T-bar and the troffer housing. The adaptor bracket includes a base portion and a wall coupled to the base portion, and the troffer housing of the existing troffer light fixture rests on the base portion when the adaptor bracket is disposed between the T-bar and the troffer housing of the existing troffer light fixture. The base portion extends horizontally and along the entire length of the adaptor bracket.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/961,209, filed Dec. 7, 2015, which is a continuation of U.S. patentapplication Ser. No. 14/447,329, filed Jul. 30, 2014, now U.S. Pat. No.9,206,948, issued Dec. 8, 2015, all of which are incorporated herein byreference in their entireties.

BACKGROUND

The invention relates generally to a system and method for retrofittingan existing troffer style light fixture. Existing troffer light fixturescan be retrofitted to include a more efficient light source, replacecomponents of a damaged troffer style light fixture, and/or otherwiseupgrade or replace an existing troffer light fixture.

A troffer light fixture is a generally square or rectangular tray likehousing and light source which is installed in a ceiling system. Theceiling system may be a dropped ceiling, ceiling grid and tile system,or other engineered ceiling system. The troffer light fixture includes ahousing which includes a top body wall and four side body walls. Mountedto the troffer housing are typically lamp sockets (e.g., for fluorescentlamps), lighting ballast which receives electrical power from wiringwithin the ceiling, and/or other components. The troffer light fixturemay further include a door which attaches to the troffer housing. Thedoor may be or include a lens and typically opens downward from thetroffer housing. It is challenging and difficult to develop a systemwhich allows for quick and easy retrofitting of an existing trofferlight fixture. It is also challenging and difficult to develop a systemwhich retrofits an existing troffer light fixture and reuses theexisting troffer housing. Further, it is challenging and difficult todevelop a system which is compatible with a variety of troffer lightfixtures.

SUMMARY

One embodiment relates to a retrofitting kit for retrofitting anexisting troffer light fixture having a troffer housing. Theretrofitting kit includes an adaptor bracket and a door assembly. Theadaptor bracket is configured to rest on a T-bar of a ceiling system,and further configured to be located between the T-bar and the trofferhousing of the existing troffer light fixture. The adapter bracketincludes a base portion and a wall coupled to the base portion, and thetroffer housing of the existing troffer light fixture rests on the baseportion when the adaptor bracket is disposed between the T-bar and thetroffer housing of the existing troffer light fixture. The base portionextends horizontally and along the entire length of the adaptor bracket.The adaptor bracket further includes a slot and a latch surface. Thedoor assembly includes a latch configured to engage the latch surface ofthe adaptor bracket, a hinge configured to interface with the slot ofthe adaptor bracket, a housing including the latch and the hinge, and alight source coupled to the housing.

Another embodiment relates to an adaptor bracket for retrofitting anexisting troffer light fixture that includes a base portion, a wall, aslot configured to receive a portion of a troffer door assembly, and alatch surface configured to engage with a latch of the troffer doorassembly. The base portion is configured to rest on a T-bar of a ceilingsystem, and further configured to be located between the T-bar and atroffer housing of the existing troffer light fixture. The wall iscoupled to the base portion, and the troffer housing of the existingtroffer light fixture rests on the base portion when the adaptor bracketis disposed between the T-bar and the troffer housing of the existingtroffer light fixture. The base portion extends horizontally and alongthe entire length of the adaptor bracket.

Another embodiment relates to a method for retrofitting an existingtroffer light fixture having a troffer housing using a door assembly.The method includes installing an adaptor bracket between the trofferhousing of the existing troffer light fixture and a T-bar of a ceilingsystem, removing a door of the existing troffer light fixture, hangingthe door assembly from the adaptor bracket, disconnecting the wiringfrom a power source to the existing troffer light fixture, wiring thedoor assembly to the wiring from the power source, closing the doorassembly, and latching the door assembly. The adaptor bracket includes abase portion and a wall coupled to the base portion, and the trofferhousing of the existing troffer light fixture rests on the base portionwhen the adaptor bracket is disposed between the T-bar and the trofferhousing of the existing troffer light fixture. The base portion extendshorizontally and along the entire length of the adaptor bracket.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an illustration of a troffer retrofit system including atroffer door assembly and two adaptor brackets according to an exemplaryembodiment.

FIG. 2A is an illustration of an existing troffer light fixture in adropped ceiling according to an exemplary embodiment.

FIG. 2B is an illustration of an existing troffer housing of an existingtroffer light fixture in dropped ceiling system according to anexemplary embodiment.

FIG. 3A is an illustration of a troffer door assembly according to anexemplary embodiment.

FIG. 3B is an illustration of a top view of a troffer door assemblyaccording to an exemplary embodiment.

FIG. 3C is an illustration of a side view of a troffer door assemblyaccording to an exemplary embodiment.

FIG. 3D is an illustration of an end view of a troffer door assemblyaccording to an exemplary embodiment.

FIG. 3E is an illustration of an exploded view of a troffer doorassembly according to an exemplary embodiment.

FIG. 3F is an illustration of a hinge of a door assembly according to anexemplary embodiment.

FIG. 3G is an illustration of a latch of a door assembly according to anexemplary embodiment.

FIG. 3H is an illustration of a troffer door assembly according to anexemplary embodiment.

FIG. 3I is an illustration of a top view of a troffer door assemblyaccording to an exemplary embodiment.

FIG. 3J is an illustration of a side view of a troffer door assemblyaccording to an exemplary embodiment.

FIG. 3K is an illustration of an end view of a troffer door assemblyaccording to an exemplary embodiment.

FIG. 4A is an illustration of a troffer door assembly having a curvedlens according to an exemplary embodiment.

FIG. 4B is an illustration of a top view of a troffer door assemblyhaving a curved lens according to an exemplary embodiment.

FIG. 4C is an illustration of a side view of a troffer door assemblyhaving a curved lens according to an exemplary embodiment.

FIG. 4D is an illustration of an end view of a troffer door assemblyhaving a curved lens according to an exemplary embodiment.

FIG. 4E is an illustration of an exploded view of a troffer doorassembly having a curved lens according to an exemplary embodiment.

FIG. 4F is an illustration of a troffer door assembly having a curvedlens according to an exemplary embodiment.

FIG. 4G is an illustration of a top view of a troffer door assemblyhaving a curved lens according to an exemplary embodiment.

FIG. 4H is an illustration of a side view of a troffer door assemblyhaving a curved lens according to an exemplary embodiment.

FIG. 4I is an illustration of an end view of a troffer door assemblyhaving a curved lens according to an exemplary embodiment.

FIG. 5A is an illustration of a troffer door assembly having threelenses according to an exemplary embodiment.

FIG. 5B is an illustration of a top view of a troffer door assemblyhaving three lenses according to an exemplary embodiment.

FIG. 5C is an illustration of a side view of a troffer door assemblyhaving three lenses according to an exemplary embodiment.

FIG. 5D is an illustration of an end view of a troffer door assemblyhaving three lenses according to an exemplary embodiment.

FIG. 5E is an illustration of an exploded view of a troffer doorassembly having three lenses according to an exemplary embodiment.

FIG. 5F is an illustration of a troffer door assembly having threelenses according to an exemplary embodiment.

FIG. 5G is an illustration of a top view of a troffer door assemblyhaving three lenses according to an exemplary embodiment.

FIG. 5H is an illustration of a side view of a troffer door assemblyhaving three lenses according to an exemplary embodiment.

FIG. 5I is an illustration of an end view of a troffer door assemblyhaving three lenses according to an exemplary embodiment.

FIG. 6A is an illustration of an adaptor bracket according to anexemplary embodiment.

FIG. 6B is an illustration of a profile view of an adaptor bracketaccording to an exemplary embodiment.

FIG. 6C is an illustration of an unfolded adaptor bracket according toan exemplary embodiment.

FIG. 7 is an illustration of a profile view of an adaptor bracketaccording to one embodiment.

FIG. 8A is an illustration of an alternative adaptor bracket accordingto an exemplary embodiment.

FIG. 8B is an illustration of a profile view of an alternative adaptorbracket according to an exemplary embodiment.

FIG. 8C is an illustration of an alternative unfolded adaptor bracketaccording to an exemplary embodiment.

FIG. 9 is an illustration of flow chart for retrofitting an existingtroffer light fixture using a door assembly according to an exemplaryembodiment.

FIG. 10A is an illustration of flow chart for retrofitting an existingtroffer light fixture using a door assembly and adaptor bracketsaccording to an exemplary embodiment.

FIG. 10B is an illustration of an existing troffer light fixture andcomponents which may be removed according to an exemplary embodiment.

FIG. 10C is an illustration of an adaptor bracket inserted between atroffer housing and a T-bar according to an exemplary embodiment.

FIG. 10D is an illustration of a hinge of a door assembly inserted intoa slot of an adaptor bracket according to an exemplary embodiment.

FIG. 10E is an illustration of a door assembly hung from an adaptorbracket according to an exemplary embodiment.

FIG. 10F is an illustration of a hinge of a door assembly engaged withan adaptor bracket according to an exemplary embodiment.

FIG. 10G is an illustration of an existing troffer light fixture whichhas been retrofit with a door assembly and adaptor brackets according toan exemplary embodiment.

FIG. 11 is a block diagram illustrating the components of door assemblyelectronics included in the door assembly according to an exemplaryembodiment.

FIG. 12A is a bottom, rear, left perspective view of a door assemblyhaving a single lens according to an exemplary embodiment.

FIG. 12B is a bottom plan view of a door assembly having a single lensaccording to an exemplary embodiment.

FIG. 12C is a top plan view of a door assembly having a single lensaccording to an exemplary embodiment.

FIG. 12D is a left elevation view of a door assembly having a singlelens according to an exemplary embodiment.

FIG. 12E is a right elevation view of a door assembly having a singlelens according to an exemplary embodiment.

FIG. 12F is a front elevation view of a door assembly having a singlelens according to an exemplary embodiment.

FIG. 12G is a rear elevation view of a door assembly having a singlelens according to an exemplary embodiment.

FIG. 13A is a bottom, rear, left perspective view of a door assemblyhaving a contour lens according to an exemplary embodiment.

FIG. 13B is a bottom plan view of a door assembly having a contour lensaccording to an exemplary embodiment.

FIG. 13C is a top plan view of a door assembly having a contour lensaccording to an exemplary embodiment.

FIG. 13D is a left elevation view of a door assembly having a contourlens according to an exemplary embodiment.

FIG. 13E is a right elevation view of a door assembly having a contourlens according to an exemplary embodiment.

FIG. 13F is a front elevation view of a door assembly having a contourlens according to an exemplary embodiment.

FIG. 13G is a rear elevation view of a door assembly having a contourlens according to an exemplary embodiment.

FIG. 14A is a bottom, rear, left perspective view of a door assemblyhaving three lenses according to an exemplary embodiment.

FIG. 14B is a bottom plan view of a door assembly having three lensesaccording to an exemplary embodiment.

FIG. 14C is a top plan view of a door assembly having three lensesaccording to an exemplary embodiment.

FIG. 14D is a left elevation view of a door assembly having three lensesaccording to an exemplary embodiment.

FIG. 14E is a right elevation view of a door assembly having threelenses according to an exemplary embodiment.

FIG. 14F is a front elevation view of a door assembly having threelenses according to an exemplary embodiment.

FIG. 14G is a rear elevation view of a door assembly having three lensesaccording to an exemplary embodiment.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings. In the drawings, similar symbols typicallyidentify similar components, unless context dictates otherwise. Theillustrative embodiments described in the detailed description,drawings, and claims are not meant to be limiting. Other embodiments maybe utilized, and other changes may be made, without departing from thespirit or scope of the subject matter presented here.

Referring now to FIG. 1, troffer door retrofit system 100 is shownaccording to one embodiment. Troffer door retrofit system 100 includesdoor assembly 101 and two adaptor brackets 103. Troffer door retrofitsystem 100 can be used to upgrade, retrofit, replace, and/or install alighting fixture in an existing troffer housing. Adaptor brackets 103may held into place in a ceiling system (e.g., a dropped ceiling) usinga T-bar of the ceiling system and an existing troffer housing (e.g., thehousing of an existing troffer light fixture which is being retrofit).Door assembly 101 can then be hung using hinges and/or latches fromslots included in adaptor brackets 103 and wired to an existing wiringsystem (e.g., the wiring system which was supplying the existing trofferlight fixture).

In alternative embodiments, troffer door retrofit system 100 includesonly door assembly 101. Door assembly 101 can include hinges and/orlatches which are positioned such that door assembly 101 can be hungfrom an existing troffer housing. For example, an existing troffer lightfixture may include a door hung from slots included in the housing ofthe existing troffer light fixture. The door may be removed, and doorassembly 101 of troffer door retrofit assembly 101 may be hung from theslots in the housing of the existing troffer light fixture. Internalcomponents (e.g., lamps and ballast) of the existing troffer lightfixture may be removed first to make room for door assembly 101 when inthe closed position.

In further embodiments, troffer door retrofit system includes doorassembly 101 and adaptor brackets 103, but adaptor brackets 103 may beoptionally used when retrofitting an existing troffer light fixture. Forexample, the hinges and latches of door assembly 101 may be positionedsuch that door assembly 101 is compatible with a wide range of and/or acommon existing troffer light fixture and its housing. The door of theexisting troffer light fixture may be removed and replaced with doorassembly 101 (e.g., without the use of adaptor brackets 103). If doorassembly 101 is not compatible with an existing troffer housing (e.g.,the hinges and or latches do not align with slots in the existingtroffer housing), adaptor brackets 103 may be used. This adaptabilitymay advantageously increase the number of existing troffer light fixturetypes (e.g., different configurations and/or different manufacturers)with which troffer door retrofit system 100 is compatible. Thus, trofferdoor retrofit system 100 may be packaged or sold with both door assembly101 and adaptor brackets 103 to increase the number of existing trofferlight fixtures which can be retrofit as described herein. In alternativeembodiments, door assembly 101 and/or adaptor brackets 103 may bepackaged or sold individually.

In some further embodiments, door assembly 101 includes hinges and/orlatches which may be repositioned on door assembly 101. For example, thehinges and/or latches may be secured in a slot which allows longitudinalmovement, and the hinges and/or latches may be secured in the desirableposition by engaging a fastener (e.g., tightening a nut and boltcombination). Advantageously, this may increase the number of existingtroffer light fixtures with which troffer door retrofit system 100 iscompatible (e.g., door assembly 101 may be compatible with a largerrange of slot configurations in existing troffer housings).

Still referring to FIG. 1, door assembly 101 can include one or morelamps which may be more efficient than the lamps in an existing trofferlight fixture. For example, door assembly 101 may include light emittingdiodes (LEDs) which are more efficient than the lamps of the existingtroffer light fixture. The existing troffer light fixture may includelamps of other types such as florescent lamps, incandescent lamps,halogen lamps, and/or less efficient LEDs. Advantageously, troffer doorretrofit system 100 may be used to replace the existing troffer lightfixture (e.g., in part while retaining the existing housing, wiring,and/or other components) and its less efficient lamps with the moreefficient lamps included in door assembly 101. Door assembly 101 may bewired to existing supplies, ballasts, and/or other power systems orelectronics (e.g., controllers, automation systems, sensors, etc.) ofthe existing troffer light fixture. Thus, an existing troffer lightfixture may be retrofit using troffer door retrofit system 100 such thatthe resulting troffer light fixture is more efficient, uses lesselectricity, gives of less heat, and/or includes other benefits. Thismay reduce the operating costs of a lighting system including one ormore troffer light fixtures (e.g., a lighting system in an officebuilding, warehouse, or home, an outdoor lighting system, and/or anylighting system including troffer light fixtures). While LED isspecifically used in many of the examples described, other types oflamps or light sources (e.g., fluorescent lamps, halogen lamps,incandescent lamps, organic LEDs, incandescent lamps, discharge lamps,liquid crystal displays, plasma displays, and/or other light sources)may be used in varying embodiments.

Troffer door retrofit system 100 and door assembly 101 may include thesame style lamps as an existing troffer light fixture or otherwise beapproximately equivalent in parameters such as efficiency, cost tooperate, lifespan, operating costs including maintenance, and/or otherparameters. However, troffer door assembly 101 may include ballast, acontroller, sensors, communication equipment, and/or other electroniccomponents which are superior to those of an existing troffer lightfixture or not included in an existing troffer light fixture.Retrofitting an existing troffer light fixture using troffer doorretrofit system 100 may therefore provide an upgrade in electronicsassociated with a lighting system, sensors associated with a lightingsystem, control of a lighting system, automation of a lighting system,and/or otherwise upgrade a lighting system other than increasing theefficiency of the system by replacing the type of lamp used.

As an additional example, troffer door retrofit system 100 may provide afurther advantage by allowing for easy replacement or repair of existingtroffer light fixtures. For example, an existing troffer light fixturemay break or otherwise need maintenance or repair (e.g., one or morelamps have burnt out or need replacing, ballast has been damaged orstops functioning properly, and/or other components require maintenanceor repair). Troffer door retrofit system 100 may be used to replacecomponents rather than repair them. Advantageously, this may be morecost effective than repairing the component (e.g., including or notincluding the long term energy savings of switching to a more efficientlamp) and may be more cost effective than replacing the entire existingtroffer light fixture with one of the same type (e.g., troffer doorretrofit system 100 may be comparable on cost and it may be quicker toinstall troffer door retrofit system 100 thereby reducing labor costs).

Referring now to FIG. 2A an existing ceiling system and existing trofferlight fixture are illustrated according to one embodiment. The ceilingsystem may be a dropped ceiling including one or more T-bars 201, 2×2ceiling tiles 203, 2×4 ceiling tiles 205, and/or other components. Theceiling system may include one or more existing troffer light fixtures207. As described herein, existing troffer light fixture 207 can beretrofit using troffer door retrofit system 100.

Existing troffer light fixture 207 can include components such as lens213, troffer housing 209, lamps 211, ballast, supply wires, and/or othercomponents.

As described in greater detail with reference to FIG. 2B, trofferhousing 209 can contain, secure, and/or support the other components ofexisting troffer light fixture 207. Troffer housing 209 can be securedby T-bar 201 of the ceiling system. For example, troffer housing 209 mayrest on T-bar 201. Troffer housing 209 may also be or include areflector for directing light emitted from one or more lamps down fromthe ceiling system.

The ceiling system may include a plurality of T-bars 201 which form aceiling grid. The ceiling grid typically has dimensions such thatceiling tiles 2′ by 2′ (e.g., 2×2 ceiling tile 203) and/or ceiling tiles2′ by 4′ (2×4 ceiling tile 205) are supported by the T-bars 201.Existing troffer light fixture 207 is sized to be supported in one of a2×2 grid location or 2×4 grid location. In further embodiments, theceiling system may have other dimensions. The dimensions of otherdevices, systems, and components described herein may be adjusted to becompatible with the other dimensions.

Typically, troffer housing 209 of existing troffer light fixture 207includes a plurality of slots which allow a panel or door to attach totroffer housing 209. The panel or door may open and close (e.g., usinglatches and hinges) to allow access to other components of existingtroffer light fixture 207. For example, the panel or door may be openedto change one or more lamps 211 of existing troffer light fixture 207.The panel or door may be or include a lens 213 or louver. The panel ordoor may also be removable from troffer housing 209 (e.g., unlatched andthe hinges removed from the slots included in troffer housing 209). Asdescribed herein, the panel or door of existing troffer light fixture207 may be removed and door assembly 101 of troffer door retrofit system100 may be installed using the slots included in the troffer housing 209of the existing troffer light fixture 207.

In some embodiments, existing troffer light fixture 207 may not includeslots for a panel or door or may include slots which are not compatiblewith door assembly 101 of troffer door retrofit system 100. Adaptorbrackets 103 may be used in conjunction with troffer housing 209 in suchcases.

Existing troffer light fixture 207 may be sized to be compatible withdifferently sized ceiling systems. For example, troffer housing 209 maybe sized the same or approximately the same as 2×2 ceiling tile 203 or2×4 ceiling tile 205. Existing troffer light fixture 207 may thereforebe secured by T-bar 201 of the ceiling system in any location sized fora corresponding ceiling tile. Advantageously, door assembly 101 and/oradaptor brackets 103 of troffer door retrofit system 100 may be sizedeither for a 2×2 ceiling system location, a 2×4 ceiling system location,or other sized systems.

With continued reference to FIG. 2A, in some cases, lamps 211 may beflorescent lamps. Florescent lamps are commonly used in troffer lightfixtures (e.g., existing troffer light fixture 207). For example,existing troffer light fixtures 207 often include florescent lamps whenused in such applications as industrial lighting, office space lighting,and/or other commercial or residential use with engineered ceilings(e.g., dropped ceilings). Door assembly 101 of troffer door retrofitsystem 100 includes LEDs in some embodiments. In such embodiments, doorassembly 101 as installed as part of troffer door retrofit system 100has several advantages over existing troffer light fixture 207 havingflorescent lamps 211. For example, door assembly 101 may reduce energyconsumption by up to 70% or more in comparison to existing troffer lightfixtures 207 having florescent lamps. Door assembly 101 and the LEDsincluded therein can have a longer life than florescent lamps.Therefore, maintenance related to the replacement of lamps is reducedthereby reducing maintenance costs and freeing up maintenance man hoursfor other tasks. LEDs of door assembly 101 also generate less heat thanflorescent lights thereby reducing the load on heating ventilation andair conditioning systems and reducing costs. Additionally, LEDs includedin door assembly 101 include fewer hazardous waste materials thanflorescent lamps. As such, the LEDs of door assembly 101 are easier torecycle at the end of their life cycle than florescent lamps. Continuingthe examples, the LEDs in door assembly 101 can provide a volumetric,even distribution of light with higher quality color rendering. Thecolor temperature of LEDs may also be easily customizable and/or changed(e.g., controlled with a controller or selected during manufacture).Therefore, the light produced by door assembly 101 including LEDs may beof superior quality in comparison to light produced by florescent lampsincluded in existing troffer light fixture 207.

Referring now to FIG. 2B, a troffer housing 209 of existing trofferlight fixture 207 is illustrated in relation to T-bar 201 of a ceilingsystem according to one embodiment. Troffer housing 209 rests on T-bar201 of the ceiling. T-bar 201 includes a horizontal portion on whichtroffer housing 209 rests. Two or four sides of troffer housing 209 reston T-bars 201; one T-bar 201 corresponding to each side of trofferhousing 209. The horizontal portion of each T-bar 201 and the spacing ofeach T-bar 201 in the ceiling grid prevents troffer housing 209 fromfalling through the ceiling system. Troffer housing 209 may be preventedfrom shifting relative to the opening between T-bars 201 by the verticalportion of T-bar 201. This may prevent lateral movement of trofferhousing 209. T-bars 201 are also configured to support ceiling tiles(e.g., 2×4 ceiling tile 205) using the same principles. T-bars 201 maybe suspended or supported from a structural ceiling (e.g., as in adropped ceiling).

Troffer housing 209 can be supported by T-bars 201 using flanges 215.Flanges 215 may have a variety of configurations. In one embodiment,flanges 215 include a first vertical portion extending downward fromtroffer housing 209, a horizontal portion which rests on T-bar 201, andan additional vertical portion (e.g., for preventing lateral movement oftroffer housing 209 in conjunction with the vertical portion of T-bar201). In further embodiments, flanges 215 may have other configurations.For example, flanges 215 may meet T-bar 201 at an angle (e.g., 45degrees), flanges 215 may not include a second or additional verticalportion, etc.

As described later in more detail, adaptor brackets 103 of troffer doorretrofit system 100 are configured to be held in place against T-bar 201in some embodiments. Adaptor brackets 103 may be inserted between thehorizontal portion of flange 215 and the horizontal portion of T-bar201. Adaptor brackets 103 may be prevented from moving laterally byengaging a portion of flange 215 such as the additional verticalportion. As a result, a portion of adaptor bracket 103 may be locatedbetween the end of flange 215 (e.g., an end formed by the additionalvertical portion) and the vertical portion of T-bar 201. Adaptorbrackets 103 can be further configured to extend horizontally so as toavoid interference with the remainder portion of flange 215 and/or otherportions of troffer housing 209.

In alternative embodiments, troffer housing 209 may be supported onT-bar 201 using the top of the vertical portion of T-bar 201 and asupport mechanism attached to troffer housing 209. Troffer housing 209may include a portion which extends at least to the horizontal portionof T-bar 201 and may overlap with T-bar 201. This may give theappearance that existing troffer light fixture 207 is flush or nearlyflush with the ceiling system. In such embodiments, adaptor bracket 103may be held in place using a combination of T-bar 201 and the abovedescribed portion of troffer housing 209 which extends near to oroverlapping with the horizontal portion of T-bar 201.

From flange 215, troffer housing 209 may extend vertically and/orhorizontally to a top portion. The top portion may continue until theflange and upward extension is mirrored to meet a second T-bar 201. Forexample and as illustrated in FIG. 2B, troffer housing 209 may have agenerally trapezoidal profile with an internal space for the componentsof existing troffer light fixture 207 such as florescent lamps, lampholders, and ballast. The side and/or top portions of troffer housing209 may be or be coated with a reflective material. The reflectivematerial may have been used to redirect light from lamps 211 downwardfrom the ceiling and/or laterally from the fixture. In some embodiments,the light source included in door assembly 101 of troffer door retrofitsystem 100 is positioned so as to use the troffer housing 209 to reflectemitted light downward and/or laterally from the ceiling.

The geometry of door assembly 101 of troffer door retrofit system 100may be configured such that a portion of door assemble 101 is containedwithin troffer housing 209. For example, door assembly 101 may have thesame or similar profile as compared to the panel or door of existingtroffer light fixture 207 when the door assembly 101 is installed andviewed from below.

Troffer housing 209 may also include slots for use with a panel or dooras previously described. Troffer housing can include one or more hingeslots 217. Hinge slots 217 are configured to accept a hinge portion(e.g., an extended flange) of the panel or door. For example, hingeslots 217 may include a first opening and a second smaller openingconnected to the first opening. The hinge portion of the panel or doormay be shaped so as to fit through the first opening, move down, and beprevented from exiting the hinge slot by the second smaller openingwhich is smaller than the hinge portion of panel or door. The panel ordoor can then be removed from troffer housing 209 by lifting the panelor door and removing the hinge portion from larger portion of hinge slot217 (e.g., the first opening). Hinge slot 217 can be located on flange215.

In some embodiments, two hinge slots 217 are included in troffer housing209. Door assembly 101 of troffer door retrofit system 100 can includetwo hinges (e.g., extended flanges) such that door assembly 101 can behung from hinge slots 217. In other embodiments, troffer housing 209 mayinclude a different number of hinge slots 217. For example, one or threehinge slots 217 may be included. Continuing the example, troffer housing209 may include no hinge slots 217. In such cases, door assembly 101 mayinclude a corresponding number of hinges, or adaptor brackets 103 may beused to hang door assembly 101.

Troffer housing 209 can also include one or more latch slots 219. Latchslot 219 may be an opening in troffer housing 209 (e.g., an opening inflange 215). Latch slot 219 allows a hook portion of a latch on thepanel or door to extend through troffer housing 209 and hook onto orotherwise interface with a portion of troffer housing 209. For example,a hook portion of a latch may extend through latch slot 219 from belowand rotate vertically to rest on or engage a horizontal portion oftroffer housing 209 (e.g., flanges 215).

In some embodiments, two latch slots 219 are included in troffer housing209. Door assembly 101 of troffer door retrofit system 100 can includetwo latches (e.g., rotatable latches with a grip and hook portion) suchthat door assembly 101 can be latched to hinge slots 217. In otherembodiments, troffer housing 209 may include a different number of latchslots 219. For example, one or three latch slots 219 may be included.Continuing the example, troffer housing 209 may include no latch slots219. In such cases, door assembly 101 may include a corresponding numberof latches, or adaptor brackets 103 may be used to hang door assembly101.

Referring now to FIGS. 3A-3E, door assembly 101 is illustrated accordingto one embodiment. As previously described, door assembly 101 of trofferdoor retrofit system 100 is hung using troffer housing 209 and/oradaptor brackets 103. The lamps within door assembly 101 can be wired tothe supply for an existing troffer light fixture 207. One or morecomponents of existing troffer light fixture 207 can be removed, anddoor assembly 101 can be closed and latched. As a result, existingtroffer light fixture 207 is retrofitted (e.g., to include LED lampsrather than existing florescent lamps).

Referring now to FIG. 3A. door assembly 101 includes a housing which mayinclude a plurality of components such as lower side frames 307, frameends 317, hinges 303, latches 301, and a lens 305. Multiple componentsmay be attached together such that door assembly 101 does not requireassembly when purchased by a consumer. In other words, door assembly 101may be manufactured using a plurality of components which arepermanently or semi-permanently assembled to create door assembly 101.

The frame components may be assembled or joined such that the frameprovides structural support to door assembly 101. The frame may furtherprovide one or more mounting points or surfaces for additionalcomponents of door assembly 101. Lower side frame 307 can be joined orattached to frame ends 317. This may form a square or rectangular frameon which other components are attached or joined. Latches 301 areattached or joined to lower side frame 307. Hinges 303 are attached orjoined to the opposite lower side frame 307.

In some embodiments, door assembly 101 includes lens 305. Lens 305 canbe transparent or translucent such that light emitted from a lightsource in door assembly 101 exits lens 305 to an area below doorassembly 101. Lens 305 may enhance the performance of the retrofittedtroffer light fixture. For example, lens 305 may be used to diffuselight, focus light, form one or more beams, filter light, and/orotherwise alter or manipulate light emitted from a light source includedin door assembly 101. Alternatively, lens 305 may not substantiallyalter the light exiting lens 305. In further embodiments, lens 305protects one or more components within door assembly 101. For example,lens 305 may limit access to LEDs included in door assembly 101.

Lens 305 can be supported by and/or attached to lower side frames 307 ofdoor assembly 101. In some embodiments, lens 305 is removable from doorassembly 101. This may allow access to one or more other components ofdoor assembly 101. For example, removing lens 305 may provide access tolamps, supply wiring, electronics, controllers, and/or other components.This allows for replacement or repair of components (e.g., replacinglamps). In some embodiments, lens 305 may rest on a portion of lowerside frames 307 and/or frame ends 317. Lens 305 may be made of adeformable material (e.g., is plastically deformable) such that lens 305may be deformed and removed from the frame of door assembly 101. Lowerside frames 307 and/or frame ends 317 may include a track or channelwhich lens 305 is inserted into. This may secure lens 305. Inalternative embodiments, lens 305 may be mounded on one or more hingesand/or include one or more latches or other features whichnon-permanently secure lens 305 in the frame of door assembly 101. Thismay allow lens 305 to be opened and provide access to internalcomponents of door assembly 101.

Lens 305 may be made of a transparent or translucent material. In someembodiments, lens 305 is made of glass or another ceramic material. Inother embodiments, lens 305 is made of acrylic or polycarbonate.Alternatively, lens 305 may be made of other polymers or plastics. Inalternative embodiments, lens 305 may be a louver. In furtheralternative embodiments, door assembly 101 does not include a lens 305.

Referring now to FIG. 3B, a top view of door assembly 101 is illustratedaccording to one embodiment. Door assembly 101 may include additionalcomponents such as upper side frame 309, top portion 311, and cover 313.Upper side frames 309 may form the top of the housing of door assembly101. As illustrated in FIG. 3D (end view), door assembly 101 may have atrapezoidal shape. Frame ends 317 form the trapezoidal ends of doorassembly 101, lower side frames 307 and lens 305 form the bottom, andupper side frames 309 form the angled top portion. Referring again toFIG. 3B, upper side frames 309 are attached or joined to lower sideframes 307. Upper side frames 309 may also be attached to or joined toframe ends 317. Upper frame ends 309 are further attached to top portion311. Top portion 311 forms the top of the trapezoidal housing of doorassembly 101. Located on top of top portion 311 is cover 313. Cover 313can cover electronic components (e.g., controllers, ballast, connectionsto supply wires, and/or other electronics) mounted on top portion 311 orotherwise contained within the space formed by cover 313 and top portion311.

In some embodiments, upper side frame 309 and/or top portion 311 areconfigured to reflect light from within door assembly 101 out throughlens 305. For example, one or more of upper side frame 309 and/or topportion 311 may be coated with a reflective material on side facing lens305. Alternatively, one or more of upper side frame 309 and/or topportion 311 may be constructed of a reflective material (e.g., a metal).In still further embodiments, door assembly 101 uses troffer housing 209of existing troffer light fixture 207 as a reflector. For example, doorassembly 101 may not include upper side frames 309, may not includeupper portion 311, or side frame 309 and/or top portion 311 may includean opening to troffer housing 209 of existing troffer light fixture 207.

Referring now to FIG. 3C, a side view of door assembly 100 isillustrated according to one embodiment. Upper side frame 309 may attachto lower side frame 307 and upper portion 311. Upper side frame 309 maybe angled so as to give door assembly 101 a trapezoidal shape.Advantageously, this may allow door assembly 101 to fit within trofferhousing 209 of existing troffer light fixture 207. As typical trofferlight fixtures have a trapezoidal housing, door assembly 101 may becompatible with a wide range of existing troffer light fixtures 207given its shape. In alternative embodiments, door assembly 101 is shapeddifferently in order to be compatible with existing troffer lightfixtures 207.

Referring now to FIG. 3D, an end view of door assembly 101 isillustrated according to one embodiment. The end of door assembly 101may be formed by frame end 317. As previously described, frame end 317may be generally trapezoidal. Hinges 303 and/or latches 301 may extendbeyond the frame of door assembly 101. This may allow door assembly 101to be hung (e.g., on troffer housing 209 of existing troffer lightfixture 207 or adaptor bracket 103) and easily opened and closed.

Referring now to FIGS. 3A-3E, door assembly 101 also includes a lightsource (not illustrated). The light source may be any device orcomponent configured to produce light, typically visible light, usingelectricity. In one embodiment, the light source is one or more LEDs.For example, the LEDs may be individual LEDs, LED ribbons including aplurality of LEDs, an LED string containing a plurality of LEDs, oranother device or package including LEDs. The LEDs may be mountedanywhere in or on the housing of door assembly 101 such that light exitsthe housing through lens 305 or the area where lens 305 would normallybe. For example, LEDs (e.g., two strips of LEDs) may be attached to thesurface of top portion 311 facing lens 305. Electronics used to controlor otherwise support the functions of the LEDs may be located in cover313. A wiring harness, supply wires, and/or other electrical connectionsmay be coupled to the LEDs to provide electrical power. The wiringharness, supply wires, and/or other electrical connections may exitcover 313. This may allow for easy retrofitting of an existing trofferlight fixture 207 as the wiring harness or supply wires may be quicklyconnected to or wired to supply wires for the existing troffer lightfixture 207. For example, the lens of the existing troffer light fixture207 may be removed, and door assembly 101 hung from either trofferhousing 209 or adaptor brackets 103. The lamps and ballast cover of theexisting troffer light fixture 207 may be removed and the supply wiresto the ballast disconnected. The wiring harness or supply wires of thedoor assembly may then be connected to the existing supply wires whichwere previously connected to the ballast of the existing troffer lightfixture 207.

In alternative embodiments, the LEDs may be located elsewhere in or onthe housing of door assembly 101. For example, the LEDs may be mountedon the side of top portion 311 facing troffer housing 209. The LEDs mayextend through one or more openings in top portion 311 and into theinterior of the housing of door assembly 101. As an additional example,the LEDs may be mounted on one or more of upper side frame 309.Alternatively, the LEDs may be mounted on a brace member (notillustrated) located within the housing of door assembly 101 and abovelens 305. LEDs may be positioned to emit light towards lens 305 and/ortowards top portion 311 and/or upper frame side 309 (e.g., thesecomponents may act as reflectors as previously described).

In other embodiments, the light source may be a lamp such as aflorescent lamp or incandescent lamp. The light source may be attachedto one or more components of door assembly 101 such that light isemitted within the housing and exits through lens 305. For example, thelight source may be attached to the inside of top portion 311. The lightsource may be attached with hardware such as lamp holders. Ballast,controllers, and/or other electronics for use with the light source maybe located between cover 313 and top portion 311.

Still referring to FIGS. 3A-3E, components may be attached to oneanother or joined together as described above. In various embodiments,various techniques may be used to assemble the components describedherein. For example, screws, rivets, nuts and bolts, and/or otherfasteners may be used to attach components to each other. Continuing theexample, glues, drying adhesives, pressure-sensitive adhesives, contactadhesives, hot adhesives, reactive adhesives, adhesive tape, and/orother adhesives may be used to attach one component to another orotherwise join components. Components may also be attached or joinedusing welding or similar techniques (e.g., TIG welding, MIG welding,spot welding such as resistive spot welding, ultrasonic welding, and/orother techniques).

In some embodiments, door assembly 101 may include a single housingwhich is produced as one piece of material. For example, a housing(e.g., including lower side frame 307, upper side frame 309, frame ends317, top portion 311, and/or other components) may be a single componentmade by stamping, machining, printing, extruding, casting, injectionmolding, and/or other manufacturing techniques.

Referring now to FIG. 3E, an exploded view of door assembly 101 is shownaccording to one embodiment. As illustrated, components of door assembly101 may include mounting points (e.g., indentations, holes, etc.) forattaching or joining two or more components. For example, lower sideframe 307 and upper side frame 309 may both include mounting points atcorresponding locations on flanges for attaching lower side frame 307 toupper side frame 309. Fasteners may be used to attach or join the twocomponents. Similarly, attachment points on lower side frame 307 and/orupper side frame 309 may be used in conjunction with fasteners to attachhinges 303 and/or latches 301.

Lower side frames 307 and/or frame ends 317 may include channels. Thechannels may give the appearance that door assembly 101 is flush withT-bar 201 when installed. Lower side frames 307 may also include aflange or other horizontal surface for receiving and/or supporting lens305. Flanges may be included in other components and used for a varietyof purposes. For example, flanges may provide additional strength tocomponents (e.g., acting as a U beam). As an additional example, flangesmay provide a surface on which to apply adhesives, spot weld twocomponents, or otherwise facilitate the joining of two components or theattachment of one component to another.

Referring now to FIG. 3F, hinge 303 is illustrated according to oneembodiment. As previously discussed, hinge 303 is included in doorassembly 101. One or more hinges 303 are used to hang door assembly 101from either troffer housing 209 of existing troffer light fixture 207 oradaptor brackets 103. Thus, existing troffer light fixture 207 can beretrofit with door assembly 101.

Hinge 303 is attached to door assembly 101. In some embodiments, hinge303 is attached to lower side frame 307. Hinge 303 is attached withfasteners 319. For example, fasteners 319 may be screws, nuts and bolts,rivets, spot welds, or other fasteners as previously described hereinfor use in attaching or joining components of door assembly 101. Inalternative embodiments, hinge 303 may be attached to or joined withdoor assembly in other locations. For example, hinge 303 may be attachedto or joined with frame end 317. In some alternative embodiments,fasteners 319 are not used to attach or join hinge 303 to door assembly101. For example, adhesive may be used. Alternatively, hinge 303 may bepart of a single piece making up the housing of door assembly 101. Forexample, hinge 303 may be part of an injection molded or milled housing.

Hinge 303 can include plate section 321. Plate section 321 may includeholes, taps, or other features used to attach hinge 303 to door assembly101. Plate section 321 may provide a surface with which to spot weldhinge 303 to door assembly 101.

Hinge 303 may include angled portion 323. Angled portion 323 can provideseparation between door assembly 101 and the components to which doorassembly 101 is attached (e.g., adaptor bracket 103 or troffer housing209 of existing troffer light fixture 207). This separation allows fordoor assembly 101 to hinge on hinge 303. Angled portion 323 may be havean angle and/or a length such that door assembly 101 appears to be flushwith the ceiling and/or troffer housing 209 of the existing trofferlight fixture 207. In alternative embodiments, angled portion 323 may bevertical rather than angled, angled by a different degree, or omittedfrom hinge 303.

Attached to the end of angled portion 323 is locking portion 325.Locking portion 325 is configured to be inserted into a correspondingslot on either troffer housing 209 of existing troffer light fixture 207or adaptor bracket 103. Locking portion 325 includes one or moreextended portions 327. This allows locking portion 325 to be insertedinto a slot having a large and small opening. Locking portion 325including extended portions 327 is inserted into the large opening ofthe slot. Hinge 303 is then lowered. While door assembly 101 is hanging,extended portions 327 prevent hinge 303 from exiting the slot asextended portions 327 make locking portion 325 larger than the smallopening of the slot. Hinge 303 can be removed from the slot by liftingand pulling door assembly 101.

In alternative embodiments, other hinges 303 are used. For example,hinge 303 may be attached with fasteners or other techniques to trofferhousing 209 or adaptor bracket 103. In other alternative embodiments,hinge 303 may function as previously described herein but have adifferent geometry. For example, locking portion 325 may act as a hookwhich hooks onto a corresponding portion of troffer housing 209 oradaptor bracket 103. As an alternative embodiment, hinge 303 may bereplaced by a flexible connector which is attached to both door assembly101 and troffer housing 209 or adaptor bracket 103. For example, doorassembly 101 may be secured to troffer housing 209 or adaptor bracket103 with a tie.

Referring now to FIG. 3G, latch 301 is illustrated according to oneembodiment. As previously described, latch 301 is attached to orincluded in door assembly 101. Latch 301 secures door assembly 101 inthe closed position by interfacing with troffer housing 209 of existingtroffer light fixture 207 or adaptor bracket 103.

Latch 301 is attached to door assembly 101. In some embodiments, latch301 is attached to lower side frame 307. Latch 301 is attached withfasteners 319. For example, fasteners 319 may be screws, nuts and bolts,rivets, spot welds, or other fasteners as previously described hereinfor use in attaching or joining components of door assembly 101. Inalternative embodiments, latch 301 may be attached to or joined withdoor assembly in other locations. For example, latch 301 may be attachedto or joined with frame end 317. In some alternative embodiments,fasteners 319 are not used to attach or join latch 301 to door assembly101. For example, adhesive may be used.

Latch 301 includes handle portion 329. Handle portion 329 extends lowerthan the frame of door assembly 101. For example, handle position 329extends below lower side frame 307. Handle portion 329 may be parallelto and in contact with the bottom surface of lower side frame 307 whenlatch 301 is engaged. This may give the appearance of latch 301 beingflush with door assembly 101. Additionally, it may reduce the chance oflatch 301 being accidently disengaged. Handle portion 329 may include alip or slanted portion which makes handle portion 329 easier to graspwhile latch 301 is engaged.

Latch 301 also includes body portion 331. Body portion 331 may includeholes, taps, or other features used to attach hinge 303 to door assembly101.

Latch 301 further includes hook portion 333. Hook portion 333 isconfigured as a hook to engage with a surface and prevent door assembly101 from swinging open. For example, hook portion 333 may be insertedthrough a slot on troffer housing 209 of existing troffer light fixture207 or adaptor bracket 103. After hook portion 333 is inserted into theslot, latch 301 may be rotated to the engaged position (e.g., asillustrated) using handle portion 329. This rotates hook portion 333such that hook portion extends out of the slot and over a horizontalsurface (e.g., a latch surface) of either troffer housing 209 ofexisting troffer light fixture 207 or adaptor bracket 103. Hook portion333 is therefore positioned such that hook portion 333 does not fitthrough the slot.

Fastener 319 may provide sufficient friction or resistance to rotationsuch that latch 301 does not move from the engaged position to thedisengaged position under the weight of door assembly 101. Fastener 319may keep latch 301 in position until actuated by applying a force onhandle portion 329.

In alternative embodiments, other latches 301 are used. For example,latch 301 may be a stationary component in relation to door assembly 101such as a magnet or magnetic material. A section of either trofferhousing 209 or adaptor bracket 103 may be or include magnetic materialor a magnet. This can allow door assembly 101 to be secured usingmagnetic force between latch 301 and the corresponding magnetic materialor magnet. In other alternative embodiments, latch 301 may be mechanicalas previously described, but latch 301 may have a different geometry.

Referring generally to FIGS. 3A-3G, the components of door assembly 101described herein may be made of a variety of materials and using avariety of manufacturing techniques. In some embodiments, one or morecomponents are made of a metal or a plurality of metals. For example,components may be made of aluminum, steel, tin, and/or other metals oralloys. In some embodiments, one or more components are made of plasticsor polymers. For example, components may be made of or include acrylic,polycarbonate, polyvinyl chloride, or other polymers. In furtherembodiments, one or more components may be made of ceramic materials.

Referring now to FIGS. 3H-3K, an alternative embodiment of door assembly101 is illustrated according to one embodiment. An isometric view, topview, side view, and end view are shown respectively. Door assembly 101can be sized squarely rather than as a rectangle as previouslyillustrated in FIGS. 3A-3G. Door assembly 101 may be square in order tooperate with ceiling systems having tiles and existing troffer lightfixtures 207 which are 2×2, 1×1, or have other square dimensions. Thisis in contrast to the door assembly illustrated in FIGS. 3A-3G which issized as a rectangle for use in a rectangle ceiling system or rectangleexisting troffer light fixture 207 (e.g., an existing 2×4 troffer lightfixture).

The components of square door assembly 101 may be the same components asthose in the rectangular door assembly 101 previously described butresized. Some components may remain the same size (e.g., hinge 303,latch 301, cover 313, the light source, etc.). Adaptor brackets 103 maybe similarly resized for use with square door assembly 101.

Referring now to FIGS. 4A-4E, an alternative embodiment of door assembly101 described with reference to FIGS. 3A-3G is illustrated. A curvedlens 405 (e.g., a contour lens) may be used rather than a flat lens.Cover 313 may be replaced as the location of door assembly 101electronics. In its place, electronics housing 413 and electronics cover415 can be used. The description of like components made in reference toFIGS. 3A-3G applies to like components illustrated and described withreference to FIGS. 4A-4E. Similarly, description of additionalcomponents (e.g., the light source), materials, attachment or joiningtechniques, and functions or operation applies as well.

Referring now to FIG. 4A, door assembly 101 can include latches 401,hinges 403, and frame ends 417. These components may be as previouslydescribed. Together with lower side frame 407, frame ends 417 may formthe basic frame of door assembly 101. Lower frame sides 407 may differfrom previously described lower frame sides 307 to accommodate curvedlens 405. As illustrated, lens 405 may be curved in contrast to the flatlens illustrated by lens 305.

Referring now to FIG. 4B, door assembly 101 can also include upper sideframes 409 and top portion 411. These components may complete thehousing of door assembly 101. Electronics housing 413 may be mounted ontop portion 411, upper side frame 409, or a combination thereof.Electronics housing 413 may perform the functions of cover 313previously described. For example, electronics housing 413 may includeelectronic components related to the light source included in doorassembly 101. Electronics housing 413 may also include wiring forconnecting door assembly 101 to an existing power supply such as supplywires disconnected from existing troffer light fixture 207. The wiringmay extend from an opening in electronics housing 413.

Referring now to FIG. 4C, a side view of door assembly 101 isillustrated according to an embodiment including electronics housing413. Lower side frame 407 may be attached or joined with upper sideframe 409. Upper side frame 409 may be attached to or joined with topportion 411. Electronics housing 413 may be mounted such thatelectronics housing is located along side upper side frame 409. This mayallow electronics housing 413 to be lower than top portion 411 or extendnot substantially above top portion 411. Advantageously, this may reducethe overall height of door assembly 101. Therefore, door assembly 101may be compatible with a greater number of troffer housings 209 ofexisting troffer light fixtures 207. In some cases, the lower overallheight of door assembly 101 may reduce the number of components whichare removed from existing troffer light fixture 207 during the retrofitprocess. For example, the lower overall height of door assembly 101 mayallow for ballast of existing troffer light fixture 207 to remain.

Referring now to FIG. 4D, an end view of door assembly 101 isillustrated according to an embodiment including electronics housing413. As previously discussed, electronics housing 413 may be locatedsuch that the overall height of door assembly 101 is not substantiallyincreased by including electronics and/or wiring.

Referring now to FIG. 4E, an exploded view of door assembly 101 is shownaccording to one embodiment. Door assembly 101 may include electronicscover 415. Electronics cover 415 may attach to electronics housing 413.Electronics cover 415 can include a flange for attaching or joiningelectronics cover 415 and electronics housing 413 to another componentof door assembly 101 (e.g., top portion 411).

As previously discussed, lower side frame 407 may be configured tosupport, secure, retain, or otherwise interface with curved lens 405.For example, lower side frame 407 may extend further toward the centerof door assembly 101 than lower side frame 307. Lower side frame 407 mayalso include a flange or other receiving portion in order to retaincurved lens 405.

Curved lens 405 (e.g., a contour lens) may be inserted and/or removedfrom door assembly 101 as previously described with reference to lens305. In alternative embodiments, curved lens 405 is fixed and cannot beremoved. Curved lens 405 or other contour lens may provide an aestheticadvantage over a flat lens. In some embodiments, curved lens 405 (e.g.,a contour lens) may focus emitted light, form a beam of emitted lightwith a desired geometry or beam pattern, or otherwise effect the lightemitted from door assembly 101.

Referring now to FIGS. 4F-4I, an alternative embodiment of door assembly101 is illustrated according to one embodiment. An isometric view, topview, side view, and end view are shown respectively. Door assembly 101can be sized squarely rather than as a rectangle as previouslyillustrated in FIGS. 4A-4E. Door assembly 101 may be square in order tooperate with ceiling systems having tiles and existing troffer lightfixtures 207 which are 2×2, 1×1, or have other square dimensions. Thisis in contrast to the door assembly illustrated in FIGS. 4A-4E which issized as a rectangle for use in a rectangle ceiling system or rectangleexisting troffer light fixture 207 (e.g., an existing 2×4 troffer lightfixture).

The components of square door assembly 101 may be the same components asthose in the rectangular door assembly 101 previously described butresized. Some components may remain the same size (e.g., hinge 403,latch 401, electronics housing 413, the light source, etc.). Adaptorbrackets 103 may be similarly resized for use with square door assembly101.

Referring now to FIGS. 5A-5E, an alternative embodiment of door assembly101 described with reference to FIGS. 3A-3G is illustrated. Two lenses505 and a center lens 506 may be used rather than a flat lens 305previously described. The description of like components made inreference to FIGS. 3A-3G applies to like components illustrated anddescribed with reference to FIGS. 5A-5E. Similarly, description ofadditional components (e.g., the light source), materials, attachment orjoining techniques, and functions or operation applies as well.

Referring now to FIG. 5A, door assembly 101 can include a plurality oflenses. Two lenses 505 may be located on the sides on center lens 506.The three lens setup may provide several advantages. For example, theuse of lenses 505 and center lens 506 may improve the aestheticappearance of door assembly 101. Lenses 505 and center lens 506 mayallow for a more complex beam pattern for the light emitted by doorassembly 101. For example, lenses 505 may be used to direct lighttowards the sides of door assembly 101 and center lens 506 may be usedto direct light below door assembly 101. Each lens (e.g., lenses 505 andcenter lens 506) may have different properties in some embodiments. Forexample, center lens 506 may be configured to produce a narrow beamwhile lenses 505 are configured to produce wide beams. Continuing theexample, the three lenses may be configured to produce light of varyingcolor temperatures or intensities.

In further embodiments, lens 506 may be a faux lens. For example, lens506 may be opaque or less transparent than lenses 505. Lens 506 mayprovide a mounting surface for the light source within door assembly101. Advantageously, this may allow the light source to be directedupward. Light emitted from the light source may be reflected from upperside frames 509 down through lenses 505 and center lens 506 if notcompletely opaque. The configuration of door assembly 101 describedherein can provide a volumetric, even-distribution of light.

In alternative embodiments, lenses 505 and center lens 506 may beoriented other than with the long axes parallel with the long axis ofdoor assembly 101. For example, lenses 505 and center lens 506 may beperpendicular to the long axis of door assembly 101.

Referring now to FIG. 5B, the housing of door assembly 101 can includelower side frame 507, upper side frame 509, frame ends 517, and topportion 511. Door assembly 101 further includes hinges 503 and latches501. These components may function as described with reference to lowerside frame 307, upper side frame 309, frame ends 317, top portion 311,hinges 303 and latches 301 and FIGS. 3A-3G. Cover 515 may function ascover 313 previously described.

Referring now to FIGS. 5C and 5D, a side view and end view,respectively, of door assembly 101 are illustrated according to oneembodiment. Door assembly 101 may have the same or substantially similarshape and geometry as door assembly 101 described with reference toFIGS. 3A-3G.

Referring now to FIG. 5E, an exploded view of door assembly 101 is shownaccording to one embodiment including three lenses. The housing of doorassembly 101 is formed by lower side frames 507, upper side frames 509,frame ends 417, and top portion 511. Attached to top portion 511 iscover 515. Held herein may be the electronic components of door assembly101.

Lenses 505 are supported, secured, and/or retained in part by lower sideframes 507. Lenses 505 angle upward from lower side frame 507 to besupported by support members 523. Support members 523 are attached orjoined to lens bracket 519. Support members 523 are attached to orjoined to lens bracket 519 and are shaped such that lenses 505 areelevated above center lens 506 at lens bracket 519. This provides lenses505 with the angled configuration previously described herein.

Also attached to lens brackets 519 are groove members 521. Grove members521 may be L shaped. Groove members 521 create a channel in which centerlens 506 is supported. In some embodiments, center lens 506 is free tomove vertically relative to groove members 521. This may allow centerlens 506 to be removed from door assembly 101 and/or provide access todoor assembly 101 by lifting center lens 506. Groove members 521 may bemounted to lens bracket 519 such that center lens 506 is positionedbelow lenses 505 where they are supported by lens bracket 519 and/orsupport members 523.

Lens bracket 519 is attached to or joined to frame ends 517. Lensbracket 519 provides support to lenses 505 and center lens 506 alongwith any additional support or positioning components. In alternativeembodiments (e.g., embodiments in which lenses 505 and center lens 506are perpendicular to the long axis of door assembly 101), lens bracket519 can be attached to or joined to other components of door assembly101.

Referring now to FIGS. 5F-5I, an alternative embodiment of door assembly101 is illustrated according to one embodiment. An isometric view, topview, side view, and end view are shown respectively. Door assembly 101can be sized squarely rather than as a rectangle as previouslyillustrated in FIGS. 5A-5E. Door assembly 101 may be square in order tooperate with ceiling systems having tiles and existing troffer lightfixtures 207 which are 2×2, 1×1, or have other square dimensions. Thisis in contrast to the door assembly illustrated in FIGS. 5A-5E which issized as a rectangle for use in a rectangle ceiling system or rectangleexisting troffer light fixture 207 (e.g., an existing 2×4 troffer lightfixture).

The components of square door assembly 101 may be the same components asthose in the rectangular door assembly 101 previously described butresized. Some components may remain the same size (e.g., hinge 503,latch 501, cover 515, the light source, etc.). Adaptor brackets 103 maybe similarly resized for use with square door assembly 101.

Generally, one or more of the previously described features orcomponents of door assembly 101 can be combined with features orcomponents from alternatively described embodiments. For example, theuser of three lenses described with respect to FIGS. 5A-5E may becombined with the use of a side mounted or portioned electronics housingas described with reference to FIGS. 4A-4E. Other combinations andembodiments are possible.

Referring now to FIGS. 6A-6C, adaptor bracket 601, one embodiment ofadaptor bracket 103 previously described herein, is illustratedaccording to an exemplary embodiment. As previously described herein,adaptor bracket 103, and the embodiment of adaptor bracket 601illustrated herein, is configured for use in retrofitting an existingtroffer light fixture 207. Adaptor bracket 601 can be placed between atroffer housing 209 of an existing troffer light fixture 207 and a T-bar201 of a ceiling system. Troffer housing 209 keeps adaptor bracket 601in place in some embodiments (e.g., the weight of troffer housing 209).Adaptor bracket 601 includes a plurality of slots 609 which accept botha hinge 303 and latch 301 depending on which is inserted into slot 601.Door assembly 101 is hung from the slots 609 on one adaptor bracket 601using hinges 303 and is latched in a closed position by securing latches301 through slots 609 on a second adaptor bracket. The second adaptorbracket 601 is located on the opposite side of troffer housing 209 fromthe first adaptor bracket 601.

Advantageously, the use of two adaptor brackets 601 allows door assembly101 to be hung under troffer housings 209 of existing troffer lightfixtures 207 which do not include slots aligning with or compatible withboth the hinges 303 and latches 301 of door assembly 101. This increasesthe number of existing troffer light fixtures 207 which can be retrofit.Additionally, adaptor brackets 601 are configured, in some embodiments,such that slots 609 can accept either a latch 301 or hinge 303 of doorassembly 101. The slots 609 on adaptor brackets 601 may also be spacedsuch that each slot 609 (of two slots 609) is an equal distance from theend of adaptor bracket 601 closet to that slot 609. Advantageously,these characteristics allow two adaptor brackets 601 to be installedwithout regard for which side of troffer housing 209 they are installedon. Door assembly 101 can be hung on either bracket, and door assembly101 will be able to latch closed using the other adaptor bracket 601.This may provide a benefit or advantage by simplifying the instillationprocess. An installer does not need to keep track of two differentadaptor brackets. Additionally, this may provide an advantage in that aplurality of existing troffer light fixtures 207 can be retrofit withdoor assemblies 101 such that all door assemblies 101 open in the samedirection. This may simplify any maintenance which is required.Furthermore, this configuration of the adaptor brackets 601 may providea benefit or advantage by simplifying the manufacturing process. Forexample, a single type of die or mold may be used.

Referring now to FIG. 6A, adaptor bracket 601 is illustrated along witha more detailed view of slot 609 and the surrounding portions accordingto one embodiment. Adaptor bracket 601 may be generally U shaped with achannel 605, lip 603, and side 607. Channel 605 is configured (e.g.,sized) to accept a portion of troffer housing 209 of an existing trofferlight fixture 607. For example, the end of troffer housing 209 or aflange of troffer housing 209 can rest on or in channel 605. The weightof troffer housing 209 may secure adaptor bracket 601 against a T-bar201 of the ceiling system.

In some embodiments, adaptor bracket 601 includes lip 603. Lip 603 canengage with an end or flange of troffer housing 209. Lip 603 can preventadaptor bracket 601 from sliding horizontally and away from T-bar 201.Troffer housing 209 may push against lip 603 in the direction of T-bar201.

Referring now to FIGS. 6A and 10C, adaptor bracket 601 can include achannel 605 which extends beyond T-bar 201. Channel 605 may extend fromT-bar 201 such that side 607 is positioned to extend within trofferhousing 209. Advantageously, this may allow slots 609 of adaptor bracket601 to be higher than the lowest surface of troffer housing 209. Thisallows door assembly 101 to be mounted using slots 609 in such a way asdoor assembly 101 is flush or nearly flush with troffer housing 209.This may improve the aesthetics of an existing troffer light fixture 207retrofit using troffer door retrofit system 100.

In alternative embodiments, side 607 may be at an angle to channel 605.This may allow channel 605 to be narrower (e.g., approximately the widthof the end or flange of troffer housing 209). Side 607 can extendvertically and horizontally such that slot 609 is positioned withintroffer housing 209. In further alternative embodiments, side 607 may beat a downward angle relative to channel 605. This may lower slot 609relative to troffer housing 209 of existing troffer light fixture 207.Advantageously, this may provide move clearance for door assembly 101 tofit at least partially within troffer housing 209 when hung and closed.This may make troffer door retrofit system 100 compatible with a widervariety of existing troffer light fixtures 207.

Referring again to FIG. 6A, side 607 includes slot 609. Slot 609 isconfigured to accept hinge 303 of door assembly 101 such that doorassembly 101 can be hung from adaptor bracket 601 using slot 609. Slot609 is configured to have a large opening and a small opening. Aspreviously described, the large portion of the opening allows hinge 303,including extended portions 327 to be inserted through slot 609. Slot609 also includes a smaller portion. When hinge 303 is lowered afterbeing inserted into slot 609, the smaller portion of slot 609 preventshinge 303 from exiting slot 609 (e.g., extended portions 327 are largerthan the smaller opening of slot 609).

Slot 609 also extends to and into latch surface 611. Latch surface 611is a horizontal surface onto which hook portion 333 of latch 301engages. Hook portion 333 of latch 301, when engaged, cannot exit slot609 due to interference of latch surface 611. When latch 301 is in adisengaged position, hook portion 333 is rotated vertically and can exitslot 609.

In alternative embodiments, latch surface 611 is at an angle to side607. In further alternative embodiments, slot 609 does not extent intolatch surface 611. For example, latch surface 611 may contain, be madeof, or include magnetic material or a magnet. Latch 301 may include amagnet as previously described for securing door assembly 101 to adaptorbracket 601.

In some embodiments, adaptor bracket 601 further includes flange 613.Flange 613 may extend at a downward angle from latch surface 711. Flange613 may prevent accidental removal of hinge 303 from slot 609 bypartially overhanging slot 609 and limiting access thereto. In otherembodiments, adaptor bracket 601 does not include flange 613.

Referring now to FIG. 7, a profile 701 of an embodiment of adaptorbracket 301 having no flange is illustrated according to one embodiment.The adaptor bracket 103 includes lip 703, channel 705, side 707, latchsurface 711 and a slot (not pictured). These components may have thesame characteristics as those discussed with reference to FIGS. 6A-6C.Latch surface 711 extends from side 711. Any flange portion 713 is notat an angle to latch surface 711. Effectively, adaptor bracket 103 doesnot include a flange 713 but rather has an elongated latch surface 711.Latch surface 711 can run for the entire length of adaptor bracket 103,or a substantial, majority, or supermajority portion thereof.Advantageously, this may simplify manufacturing of adaptor bracket 103as material. For example, material may not be removed to form twodistinct latch surfaces 711 (e.g., as illustrated in FIG. 6A withreference to latch surfaces 611). Fewer cuts may be required to produceadaptor bracket 601. In embodiments where the latch surface 711 runs forthe entire or a large portion of the length of adaptor bracket 103, anadditional advantage may be provided in that latch surface 711 (or latchsurface 611 as illustrated in FIG. 6A) covers the empty space betweendoor assembly 101 and troffer housing 209 of the existing troffer lightfixture 207. This can provide a befit in that contaminants may beprevented, in whole or in part, from entering the ceiling system,airflow may be prevented, in whole or in part, from exiting the ceilingsystem (e.g., in a plenum rated ceiling application), and/or theretrofit light fixture may have a more aesthetically pleasingappearance.

Referring again to FIG. 6A, as illustrated, latch surface 611 and/orflange 613 may run for only a portion of the length of adaptor bracket601. This may allow for the use of adaptor bracket 601 and troffer doorretrofit system 100 with plenum rated ceilings (e.g., ceiling systems inwhich air returning to or being supplied by a heating ventilation and/orair condition system moves through the plenum space created by the dropceiling and the structural ceiling). The ceiling system in which thetroffer door retrofit system 100 is installed may be used to circulateair in the building containing the ceiling system. To provide for airreturns or air supply to or from the plenum space in the ceiling system,adaptor bracket 601 can be vented. Latch surface 611 and/or flange 613may run for only a portion of the length of adaptor bracket 601 toprovide for venting. When hung using hinges 303, latches 301, and thecorresponding slots 609 and latch surfaces 611 of adaptor brackets 601,door assembly 101 may be separated from adaptor bracket 601 by adistance. In some embodiments, this distance is substantially the widthof attachment surface 611 and/or flange 613. Therefore, in embodimentsin which latch surface 611 and/or flange 613 do not run the entirelength of adaptor bracket 601, a vent space is created between doorassembly 101 and adaptor bracket 601. Advantageously, this vent spacemay be used as an air supply or air return for use in a plenum ceilingsystem (e.g., for return of room air and/or supply of conditioned air ina heating ventilation and/or air conditioning system). This feature ofsome embodiments of troffer door retrofit system 100 can be used to addadditional supplies or returns when retrofitting existing troffer lightfixtures 207 of a plenum ceiling system. This feature can also be usedto retrofit existing troffer light fixtures 207 which include a supplyor return for use in a plenum ceiling system.

In alternative embodiments, lip 603 of adaptor bracket 601 engages withT-bar 201. For example, lip 603 may be or include a hook which engagesthe vertical portion of T-bar 201. The hook portion of lip 601 may slipover the vertical portion of T-bar 201. Advantageously, this may preventadaptor bracket 601 from moving horizontally relative to T-bar 201.Furthermore, adaptor bracket 601 may be held in place by the hookportion without relying on or using the weight of troffer housing 209 tosecure adaptor bracket 601.

In other alternative embodiments, adaptor bracket 601 does not rest onor connect to T-bar 201. For example, adaptor bracket 201 may be mountedto troffer housing 209 of an existing troffer light fixture 207. Adaptorbracket 601 may include a hook, latch or other mechanism to attachadaptor bracket 601 to troffer housing 209 using existing slots introffer housing 209.

Referring now to FIG. 6B, a profile view of adaptor bracket 601 isillustrated according to one embodiment. Adaptor bracket 601 may beproduced by folding sheet metal in some embodiments. The result may bethe profile as illustrated. Lip 603 may be at a 90 degree angle relativeto channel 605. Side 607 may be at an additional 90 degree anglerelative to channel 605. A further 90 degree fold from side 607 maycreate latch surface 611. And, a 58 degree fold can create flange 613.These angles are illustrative only. Other angles may be used to definethe portions of adaptor bracket 601 described herein. The anglesdescribed herein may be include radii or be chamfered in someembodiments.

Referring now to FIG. 6C, adaptor bracket 601 is illustrated prior tobeing folded according to one embodiment. A piece of sheet metal may becut to provide the shape and dimensions of adaptor bracket 601. Slot 609may also be cut from the sheet metal. The sheet metal may then be foldedto create adaptor bracket 601 as described herein.

In some embodiments, adaptor bracket 601 is made of metal as previouslydescribed. For example, adaptor bracket 601 may be made of or includegalvanized steel, aluminum, or other metals or alloys. In otherembodiments, adaptor bracket 601 may be made of other materials. Forexample, adaptor bracket 601 may be made of polymers such as acrylic,polyvinyl chloride, or other plastics. As previously discussed, adaptorbracket 601 may be made using folding techniques. In other embodiments,adaptor bracket 601 may be made using other techniques. For example,adaptor bracket 601 may be made using techniques such as injectionmolding, casting, machining, and/or a combination of these and othertechniques.

Referring now to FIGS. 8A-8C, adaptor bracket 801, one embodiment ofadaptor bracket 103 previously described herein, is illustratedaccording to an exemplary embodiment. Adaptor bracket 801 is configuredto rest, at least partially, on T-bar 201. Adaptor bracket 801 isfurther configured to engage with an end or flange of a troffer housing209 of an existing troffer light fixture 207. As previously described,adaptor bracket 801 includes slots 809 which allows door assembly 101 tobe hung from or latched to adaptor bracket 801. Generally, thedescription of adaptor bracket 601 with reference to FIGS. 6A-6C isapplicable to adaptor bracket 801. For example, the materials andmanufacturing techniques may be the same. Additionally, similar partsmay perform similar functions.

Referring now to FIG. 8A, adaptor bracket 801 includes channel 807,first side 803, and second side 811. The end of or a flange of a trofferhousing 209 of an existing troffer light fixture 207 can be received bythese components. This may allow the weight and geometry of trofferhousing 209 to keep adaptor bracket 801 in place on T-bar 201. Channel807 can rest on T-bar 201.

In some embodiments, first side 803 prevents adaptor bracket 801 frommoving horizontally and away from T-bar 201. Troffer housing 209 andfirst side 803 interfere with one another such that horizontal movementaway from T-bar 201 is prevented. In some embodiments, first side 803may be in contact or nearly in contact with the vertical portion ofT-bar 201. This may prevent or substantially limit horizontal movementof adaptor bracket 801 towards T-bar 201 as T-bar 201 and first side 803would interfere.

In some embodiments, adaptor bracket 801 further includes flange 805.Flange 805 can extend from first side 803 over channel 807. In someembodiments, flange 805 engages with and end of or flange of trofferhousing 209. Flange 805 may assist in preventing adaptor bracket 801from moving relative to troffer housing 209 and/or T-bar 201. Flange 805may also prevent troffer housing 209 from inadvertently exiting channel807.

First side 803 and flange 805 may include one or more tabs 809. Tabs 809and flanges 805 can be used to elevate the troffer housing 209 of anexisting troffer light fixture 207 which is being retrofit with trofferdoor retrofit system 100. The troffer housing 209 can rest on top offlange 805. This lifts the troffer housing 209 to a higher position thanas installed (e.g., resting on T-bar 201). Channel 807 rests on T-bar201 with flange 805 elevated above channel 807 and T-bar 201 by firstside 803. The troffer housing 209 is elevated above T-bar 201 as itrests on flange 805. Tabs 809 advantageously prevent adaptor bracket 801from sliding horizontally and away from T-bar 201. Tabs 809 can contactthe edge of troffer housing 209 resting on flange 805 and thisinterference prevents adaptor bracket 801 from becoming disengage fromT-bar 201 and/or troffer housing 209.

Advantageously, lifting troffer housing 209 of existing troffer lightfixture 207 higher in relation to the T-bar 201 provides additionalspace in which to hang door assembly 101. This provides an advantage inthat troffer door retrofit system 100 is compatible with existingtroffer light fixtures 207 with a shallower troffer housing 209. Thetroffer housing 209 is lifted by adaptor bracket 801 including flange805 providing more space to hang door assembly 101. Therefore, trofferdoor retrofit system 100 is compatible with a wider range of existingtroffer light fixtures 207. Additionally, the additional space providedby adaptor bracket 801, may reduce, partially or completely, the numberof components (e.g., ballast, ballast cover, lamps, etc.) which areremoved from existing troffer light fixture 207 to make room for doorassembly 101 when closed (e.g., latched and extending into trofferhousing 209).

Adaptor bracket 801 can provide an additional advantage in that adaptorbracket 801 can be used for standard retrofitting and retrofitting inwhich additional space is needed. A single adaptor bracket 801 can beused for either case, reducing the types of adaptor brackets 103 whichare manufactured or provided. In a standard installation, trofferhousing 209 can be inserted into adaptor bracket 801 such that the edgeof troffer housing 209 rests in channel 807 and is secured by first side803 and/or flange 805. In an installation in which additional space isdesired, troffer housing 209 can be lifted and placed on adaptor bracket801. The edge of troffer housing 209 can rest on top of flange 805. Theedge of troffer housing 209 can be secured with tabs 809.

Adaptor bracket 801 further includes second side 811, latch surface 815,and slot 813. As described with reference to corresponding components inFIGS. 6A-6C, these components allow door assembly 101 to be hung fromadaptor bracket 801 or latched to adaptor bracket 801 using hinges 303and latches 301 respectively.

Referring now to FIG. 8B, a profile view of adaptor bracket 801 isillustrated according to one embodiment. Adaptor bracket 801 may beproduced by folding sheet metal in some embodiments. The result may bethe profile as illustrated latch surface 815 may be at a 90 degree angleto second side 811 which in turn is at a 90 degree angle from channel807, First side 803 may also be at a 90 degree angle from channel 807.Tab 809 may continue at the same angle as first side 803 relative tochannel 807. Flange 805 may be at a 90 degree angle from first side 803.These angles are illustrative only. Other angles may be used to definethe portions of adaptor bracket 801 described herein. The anglesdescribed herein may be include radii or be chamfered in someembodiments.

Referring now to FIG. 6C, a portion of adaptor bracket 801 isillustrated prior to being folded according to one embodiment. A pieceof sheet metal may be cut to provide the shape and dimensions of adaptorbracket 801. Slot 813 may also be cut from the sheet metal. The sheetmetal may then be folded to create adaptor bracket 801 as describedherein.

Generally, one or more of the previously described features orcomponents of adaptor brackets 103 can be combined with features orcomponents from alternatively described embodiments. Other combinationsand embodiments are possible.

Referring now to FIG. 9, a flow chart of method 900 for retrofitting anexisting troffer light fixture 207 using troffer door retrofit system100. An installer disconnects power to the existing troffer lightfixture 207 (901). For example, an installer may turn off a light switchwhich controls the electrical supply (e.g., interrupts the electricalsupply) to existing troffer light fixture 100. As an alternativeexample, an installer can disconnect power to existing troffer lightfixture 207 using a breaker.

The installer can remove the door of the existing troffer light fixture207 (903). In some embodiments, the installer removes the door afterdisconnecting the power. In alternative embodiments, the installerremoves the door prior to turning of the power. As previously describedherein, the existing troffer light fixture 207 can include a door. Thedoor may be or include the lens or a louver of the existing trofferlight fixture 207. Removing the door can include unlatching the doorfrom the troffer housing 209 of the existing troffer light fixture 207.Removing the door can also include unhinging the door from the trofferhousing 209. For example, the hinges of the door may be lifted out ofslots included in the troffer housing 209.

The installer may determine if clearance in the housing 209 of theexisting troffer light fixture 207 is sufficient to permit installationof door assembly 101 (905). This can include taking one or measurements.This may also or alternatively include consulting an instruction manualwith instructions for retrofitting a particular existing troffer lightfixture 207. For example, the instruction manual may have been preparedwith the knowledge of the clearances of many types of existing trofferlight fixtures 207. Based on the particular make or model of theexisting troffer light fixture 207 being retrofit, the instructions mayinstruct the installer that clearance does or does not permitinstallation of door assembly 101 without removing one or morecomponents of existing troffer light fixture 207.

If clearance does not permit installation of door assembly 101, theinstaller can remove lamps, a ballast cover, and/or the ballast ofexisting troffer light fixture 207 (907). Removing these components, asubset of these components, and/or other components of existing trofferlight fixture 207 can provide sufficient clearance for the installationof door assembly 101.

If clearance does permit instillation of door assembly 101, lamps, aballast cover, ballast, and/or other components of existing trofferlight fixture 207 may be left within troffer housing 209.

The installer can hang the door assembly 101 from the existing trofferhousing 207 (909). As previously described herein, the hinges 303 ofdoor assembly 101 can be configured to operate with slots of a trofferhousing 209 of the existing troffer light fixture 207. Hanging doorassembly 101 from the troffer housing 209 can include inserting hinges303 of the door assembly 101 into a slot on troffer housing 209. Doorassembly 101 can then be lowered such that hinges 303 do not exit theslots in troffer housing 209.

The installer can wire door assembly 101 to a power supply for theexisting troffer light fixture 207 (909). This can include firstremoving power supply wires from the ballast or another component of theexisting troffer light fixture 207. The power supply wires may then bewired (e.g., joined to, using a twist-on wire connector) a power supplywire for door assembly 101. The power supply wire for door assembly 101may be extending from a cover 313, electronics housing 413, or otherportion of door assembly 101. The installer may also complete any wiringfor other components of door assembly 101. For example, the installermay wire other electronics of door assembly 101 such as controllers andsensors to existing or newly installed components related to existingtroffer light fixture 207. Alternatively, door assembly 101 can be wiredto already existing components such as controllers or sensors includedin or related to existing troffer light fixture 207.

The installer can close door assembly 101 and secure latches 301 of doorassembly 101 (913). This can include positioning latches 301 of doorassembly 101 in the disengaged position. The door assembly 101 can beclosed by pivoting it on hinges 303. As door assembly 101 is closed,latches 301 can enter slots included in troffer housing 209. The latchescan then be positioned in a closed position such that latches 301interact with troffer housing 209 to prevent door assembly 101 fromopening.

If at any point prior to or during the performance of method 900, theinstaller determines that the hinges 303 and/or latches 301 of doorassembly 101 do not align with or are otherwise incompatible withtroffer housing 209 of existing troffer light fixture 207, the installermay use adaptor brackets 103 to perform the retrofit. Additionally, ifthe installer determines that there is insufficient clearance even afterremoving components of existing troffer light fixture 207, the installercan use adaptor brackets 103 to perform the retrofit.

As described above and elsewhere herein, an existing troffer lightfixture 207 can be retrofit using only door assembly 101. In otherembodiments described later and elsewhere herein, an existing trofferlight fixture 100 can be retrofit using adaptor bracket 103 as well.Advantageously, either method of retrofitting can be performed withoutthe use of tools. For example, no fasteners, drills, screwdrivers, wirecutters, or other tools are required to complete the retrofit. In someembodiments, even the twist-on wire connector may be salvaged fromexisting troffer light fixture 207. In one embodiment, no tools arerequired to attach any component (e.g., adaptor bracket 103) to trofferhousing 209 of existing troffer light fixture 207. Advantageously,retrofitting without the use of tools may decrease the time taken toperform the retrofit. This may reduce costs and/or otherwise speed upthe retrofitting of one or a plurality of existing troffer lightfixtures 207. The retrofit methods described herein may also allow forretrofitting of an existing troffer light fixture 207 without disruptionof existing ceiling tiles and/or without the removal of existingfixtures. This may reduce the complexity and/or risk of damage from theretrofit process.

Referring now to FIGS. 10A-10E, a retrofit method is described andillustrated according to an exemplary embodiment. This retrofit methodincludes the use of adaptor brackets 301. As previously described, thismethod may be a continuation of the method for retrofitting using doorassembly 101 only (e.g., adaptor brackets 103 become necessary toretrofit existing troffer light fixture 207) in some embodiments.

Referring now to FIG. 10A, a flow chart for method 1000 of retrofittingan existing troffer light fixture 207 using adaptor bracket 103 isillustrated according to an exemplary embodiment. An installer mayremove the door of an existing troffer light fixture 207 and mayoptionally remove components such as lamps, a ballast cover, ballast,and/or other components from the existing troffer light fixture 207(1001). The installer can disconnect power to the existing troffer lightfixture 207 prior to this if power has not already been disconnected. Aspreviously described, components of existing troffer light fixture 207may be removed if there is not sufficient clearance for door assembly101. With additional reference to FIG. 10B, troffer door 213 may beremoved by unlatching troffer door 219 from troffer housing 209. Whiletroffer door 213 is hanging or after it has been removed (e.g., bylifting it from slots in troffer housing 209), the installer can removecomponents of existing troffer light fixture 207 such as lamps 211,ballast cover 1221, lamp holders 1223, and/or ballast 1225. If clearancepermits, these components may be abandoned inside troffer housing 209 ofthe existing troffer light fixture 207.

Referring again to FIG. 10A, the installer can lift troffer housing 209and slide in adaptor brackets 103 between troffer housing 209 and T-bar201 (1003). With reference to FIG. 10C, One side of troffer housing 209can be lifted. While lifted, adaptor bracket 203 can be inserted betweentroffer housing 209 and T-bar 201. The Troffer housing 209 can then belowered. This process can be repeated for the second adaptor bracket103.

Referring again to FIG. 10A, the installer can hang door assembly 101using hinges 303 from one of the adaptor brackets 103 (1005). Withreference to FIGS. 10D and 10E, this can include inserting hinge 303through slot 609 of adaptor bracket 103. Door assembly 101 can belowered such that hinge 303 does not exit slot 609 of adaptor bracket103.

Referring again to FIG. 10A, the installer can wire door assembly 101 tothe power supply of existing troffer light fixture 207 (1007). Withreference to FIG. 10B, Existing troffer light fixture 207 power supplywires 1227 may be removed from ballast 1225. Power supply wires 1227 canthen be connected to supply wires extending from door assembly 101.

Referring again to FIG. 10A, the installer can close door assembly 101and secure latches 301 (1009). With reference to FIG. 10F, the installerinserts latches 301 through slot 609 of adapter bracket 103 whilelatches 301 are in the disengaged position and while closing doorassembly 101. The installer then rotates latches 301 to the engagedposition and latches 301 engage with a portion of the adaptor bracket301. Referring now to FIG. 10G, this results in a retrofitted existinglight fixture having door assembly 101.

Referring now to FIG. 11, components of door assembly electronics 1101are illustrated according to one embodiment. Door assembly 101 caninclude a various door assembly electronics 1101 in various embodiments.In various embodiments, door assembly electronics 1101 are locatedwithin cover 313, electronics housing 413 and electronics cover 415, orcover 515. In further embodiments, one or more components or portionsthereof can be located partially or completely outside of a cover orhousing. Door assembly electronics 1101 can control light output of LEDsincluded in door assembly 101, provide power to LEDs in door assembly101, and/or perform other functions.

In some embodiments, door assembly electronics 1101 include a powersupply 1111. Power supply 1111 can be one or more electrical supplywires which enter cover 313, electronics housing 413 and electronicscover 415, or cover 515. Power supply 1111 can include furthercomponents such as capacitors, modulators, transformers, batteries,and/or other components to regulate, alter, modify, or otherwise provideelectrical power to door assembly electronics 1101 and/or LEDs in doorassembly 101.

In some embodiments, door assembly electronics 1101 include driver 1109.Driver 1109 can be a driver for driving or otherwise providing power toLEDs within door assembly 101. Driver 1109 may be electrically coupledto one or more LEDs, LED strips, and/or other LEDs through wiring. Thewiring may exit cover 313, electronics housing 413 and electronics cover415, or cover 515. Driver 1109 can control electrical power supplied tothe LEDs using techniques such as pulse width modulation and/or othertechniques. Driver 1109, by controlling the supply of electrical powerto the LEDs, can control the light output of the LEDs. Driver 1109 cancontrol the intensity of the light output from the LEDs, control thecolor temperature of light output by the LEDs, dim the LEDs, turn on oroff the LEDs, and/or otherwise alter or control the light output fromthe LEDs. Driver 1109 can be coupled to control circuit 1103. Driver1109 can be controlled by control circuit 1103.

In some embodiments, door assembly electronics 1101 include controlcircuit 1103. Control circuit 1103 may contain circuitry, hardware,and/or software for facilitating and/or performing the functionsdescribed herein. The control circuit 1103 may handle inputs, processinputs, run programs, handle instructions, route information, controlmemory 1107, control a processor 1105, process data, generate outputs,communicate with other devices or hardware, and/or otherwise performgeneral or specific computing tasks. In some embodiments, the controlcircuit 233 includes a processor 1105 and/or memory 1107. Controlcircuit 1103 can perform functions such as controlling driver 1109 inresponse to inputs, receive inputs from transceiver 113, receive inputslocally (e.g., through a user interface, buttons, switches, etc.),receive inputs from sensor circuitry 1115, control sensor circuitry1115, control transceiver 1113 (e.g., send or receive communicationsusing transceiver 1113), and/or perform other functions related to doorassembly 101 and/or other light fixtures or devices.

Processor 1105 may be implemented as a general-purpose processor, anapplication specific integrated circuit (ASIC), one or more fieldprogrammable gate arrays (FPGAs), a digital-signal-processor (DSP), agroup of processing components, or other suitable electronic processingcomponents. Memory 1107 is one or more devices (e.g. RAM, ROM, FlashMemory, hard disk storage, etc.) for storing data and/or computer codefor facilitating the various processes described herein. Memory 1107 maybe or include non-transient volatile memory or non-volatile memory.Memory 1107 may include database components, object code components,script components, or any other type of information structure forsupporting various activities and information structures describedherein. Memory 1107 may be communicably connected to processor 1105 andprovide computer code or instructions to processor 1105 for executingthe processes described herein. Memory 1107 and/or the control circuit1103 may facilitate the functions described herein using one or moreprogramming techniques, data manipulation techniques, and/or processingtechniques such as using algorithms, routines, lookup tables, arrays,searching, databases, comparisons, instructions, etc.

In some embodiments, door assembly electronics 1101 include transceiver1113. Transceiver 1113 may be a wireless transceiver used to send and/orreceive wireless communications. For example, transceiver 1113 may be atransceiver which sends and/or receives radio frequency transmissionsusing protocols and/or hardware related to WiFi, Zigbee, Bluetooth, orother types of communication. In other embodiments, transceiver 1113uses communication techniques other than the use of radio frequencytransmissions. For example, transceiver 1113 may use ultrasound,optical, infrared, and/or other communications techniques. Transceiver1113 can provide control signals to control circuit 1103. In response tocontrol signals (e.g., sent from a control device such as a mobilephone, computer, remote, or other device), control circuit 1103 cancontrol the light output of door assembly 101 using driver 1109. Forexample, control circuit 1103 can adjust the light intensity, colortemperature, turn on or off LEDs, or otherwise change the light outputof door assembly 101 using driver 1109.

In some embodiments, control circuit 1103 can control transceiver 1113in order to transmit communication signals. Control circuit 1103 cantransmit information, using transceiver 1113, related to the functionsof door assembly 101, the light output of door assembly 101, and/orsensor information received by sensor circuitry 1115. For example,control circuit 1103 can cause the transition of information, usingtransceiver 1113, including diagnostic information, whether doorassembly 101 is currently on or off, the light intensity being producedby door assembly 101, whether motion has been detected by sensorcircuitry 1115, and/or other information. In some embodiments,transceiver 1113 transmits this and/or other information to mobilephones, computers, remotes, and/or other devices. In furtherembodiments, transceiver 1113 transmits this information to one or moreother door assemblies 101.

In some embodiments, door assembly 1101 includes sensor circuitry 1115.Sensor circuitry 1115 can be controlled by control circuit 1103. Sensorcircuitry 1115 can also provide sensor information and/or controlsignals to control circuit 1103. Sensor circuitry may include one ormore logic modules 1117, memory 1119, and/or sensors 1121. Sensorcircuitry can use these and/or other components to provide door assemblyelectronics 1101 information regarding the environment in which doorassembly 101 operates. For example, sensor circuitry 1115 can detectmotion with a motion sensor. In response to detecting motion (e.g.,using a motion sensor 1121 and processing the data using memory 1119and/or logic module 1117), sensor circuitry 1115 can provide theinformation and/or a control signal to control circuit 1103 which causescontrol circuit 1103 to take action (e.g., turning on one or more LEDs,adjusting the intensity and/or color temperature of the light output,etc.). As an additional example, sensor circuitry 1115 can determine theintensity or amount of light surrounding door assembly 101. In responseto determining the amount or intensity of light (e.g., using a lightsensors 1121, memory 1119, a threshold value and/or logic module 1117),sensor circuitry 1115 can provide the information and/or a controlsignal to control circuit 1103 which causes control circuit 1103 to takeaction (e.g., adjust the light output using driver 1109 to compensatefor low light by increasing the light output, decrease the light outputin response to high levels of ambient light, etc.).

Sensor circuitry 1115 may contain circuitry, hardware, and/or softwarefor facilitating and/or performing the functions described herein.Sensor circuitry 1115 may handle inputs, process inputs, run programs,handle instructions, route information, control memory 1119, control oruse a logic module 1117, process data, generate outputs, communicatewith other devices or hardware, and/or otherwise perform general orspecific computing tasks. Sensor circuitry 1115 can be or include anapplication specific integrated circuit (ASIC), one or more fieldprogrammable gate arrays (FPGAs), a digital-signal-processor (DSP), agroup of processing components, or other suitable electronic processingcomponents. Memory 1119 is one or more devices (e.g. RAM, ROM, FlashMemory, hard disk storage, etc.) for storing data and/or computer codefor facilitating the various processes described herein. Memory 1119 maybe or include non-transient volatile memory or non-volatile memory.Memory 1119 may include database components, object code components,script components, or any other type of information structure forsupporting various activities and information structures describedherein. Memory 1119 may provide computer code or instructions forexecuting the processes described herein. Memory 1119 and/or the sensorcircuitry 1115 may facilitate the functions described herein using oneor more programming techniques, data manipulation techniques, and/orprocessing techniques such as using algorithms, routines, lookup tables,arrays, searching, databases, comparisons, instructions, etc.

Logic module 1117 may be implemented as hardware and/or software. Logicmodule 1117 may be stored in or use memory 1119. Logic module 1117 canprovide code or instructions for carrying out or facilitating thefunctions of sensor circuitry 1115 described herein. Alternatively,logic module can carry out these functions directly. Logic module 1117can be used to perform tasks such as comparing sensor data to thresholdvalues, determining if movement has occurred using a variety oftechniques, measuring ambient light, comparing ambient lightmeasurements to threshold values, formatting control signals for controlcircuit 1103, and/or perform other tasks or functions to facilitate theoperation of door assembly 101 as described herein.

In some embodiments, sensor circuitry 1115 includes one or more sensors1121. Sensors 1121 can be any type of sensor. In one embodiment, sensor1121 is or includes a motion sensor. For example, sensor 1121 may be orinclude an infrared motion sensor, ultrasound motion sensor, projectedcapacitance motion sensor, and/or other type of motion sensor. In otherembodiments, sensor 1121 can be or include a light sensor. For example,sensor 1121 may be or include a photodetector, bolometer, photoresister,or other light sensor. In still further embodiments, sensor 1121 can beor include other types of sensors such as temperature sensors, humiditysensors, and/or other sensors. Sensor 1121 may be located partially orwholly outside of cover 313, electronics housing 413 and electronicscover 415, or cover 515.

Referring now to FIGS. 12A-12G, door assembly 101 is illustratedaccording to one embodiment in which door assembly 101 includes a singlelens. A bottom, rear, left perspective view, bottom plan view, top planview, left elevation view, right elevation view, front elevation view,and rear elevation view are illustrated by FIGS. 12A-12G respectively.The single lens can provide light output from door assembly 101 havingspecific characteristics as previously described herein. In someembodiments, the single lens further provides an aesthetically pleasingdesign. Various embodiments have single lenses of varyingconfigurations, shapes, and/or other characteristics.

Referring now to FIGS. 13A-13G, door assembly 101 is illustratedaccording to one embodiment in which door assembly 101 includes acontour lens. A bottom, rear, left perspective view, bottom plan view,top plan view, left elevation view, right elevation view, frontelevation view, and rear elevation view are illustrated by FIGS. 13A-13Grespectively. The contour lens can provide light output from doorassembly 101 having specific characteristics as previously describedherein. In some embodiments, the contour lens further provides anaesthetically pleasing design. Various embodiments have contour lensesof varying configurations, shapes, and/or other characteristics.

Referring now to FIGS. 14A-14G, door assembly 101 is illustratedaccording to one embodiment in which door assembly 101 includes a threelenses. A bottom, rear, left perspective view, bottom plan view, topplan view, left elevation view, right elevation view, front elevationview, and rear elevation view are illustrated by FIGS. 14A-14Grespectively. The three lenses can provide light output from doorassembly 101 having specific characteristics as previously describedherein. In some embodiments, the three lenses further provides anaesthetically pleasing design. Various embodiments have three lenses ofvarying configurations, shapes, and/or other characteristics.

The present disclosure contemplates methods, systems and programproducts on any machine-readable media for accomplishing variousoperations. The embodiments of the present disclosure may be implementedusing existing computer processors, or by a special purpose computerprocessor for an appropriate system, incorporated for this or anotherpurpose, or by a hardwired system. Embodiments within the scope of thepresent disclosure include program products comprising machine-readablemedia for carrying or having machine-executable instructions or datastructures stored thereon. Such machine-readable media can be anyavailable media that can be accessed by a general purpose or specialpurpose computer or other machine with a processor. By way of example,such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, CD-ROMor other optical disk storage, magnetic disk storage or other magneticstorage devices, or any other medium which can be used to carry or storedesired program code in the form of machine-executable instructions ordata structures and which can be accessed by a general purpose orspecial purpose computer or other machine with a processor. Wheninformation is transferred or provided over a network or anothercommunications connection (either hardwired, wireless, or a combinationof hardwired or wireless) to a machine, the machine properly views theconnection as a machine-readable medium. Thus, any such connection isproperly termed a machine-readable medium. Combinations of the above arealso included within the scope of machine-readable media.Machine-executable instructions include, for example, instructions anddata which cause a general purpose computer, special purpose computer,or special purpose processing machines to perform a certain function orgroup of functions.

Although the figures may show a specific order of method steps, theorder of the steps may differ from what is depicted. Also two or moresteps may be performed concurrently or with partial concurrence. Suchvariation will depend on the software and hardware systems chosen and ondesigner choice. All such variations are within the scope of thedisclosure. Likewise, software implementations could be accomplishedwith standard programming techniques with rule based logic and otherlogic to accomplish the various connection steps, processing steps,comparison steps and decision steps.

While various aspects and embodiments have been disclosed herein, otheraspects and embodiments will be apparent to those skilled in the art.The various aspects and embodiments disclosed herein are for purposes ofillustration and are not intended to be limiting, with the true scopeand spirit being indicated by the following claims.

What is claimed is:
 1. A retrofitting kit for retrofitting an existingtroffer light fixture having a troffer housing, comprising: an adaptorbracket configured to rest on a T-bar of a ceiling system, and furtherconfigured to be located between the T-bar and the troffer housing ofthe existing troffer light fixture, the adapter bracket including: abase portion and a wall coupled to the base portion, the troffer housingof the existing troffer light fixture is supported along a full lengththereof by the base portion when the adaptor bracket is disposed betweenthe T-bar and the troffer housing of the existing troffer light fixture,wherein the base portion extends horizontally and along the entirelength of the adaptor bracket; a slot; and a latch surface; and a doorassembly including: a latch configured to engage the latch surface ofthe adaptor bracket; a hinge configured to interface with the slot ofthe adaptor bracket; a housing including the latch and the hinge; and alight source coupled to the housing.
 2. The system of claim 1, whereinthe adaptor bracket has a first end and an opposing second end, whereinthe base portion extends horizontally an entire distance between thefirst end and the opposing second end of the adaptor bracket.
 3. Thesystem of claim 2, wherein the slot is structured to accept both thehinge and the latch of the door assembly.
 4. The system of claim 3, thewall defining a first wall, wherein the first wall is coupled to a firstside of the base portion, the adaptor bracket further comprising asecond wall coupled to an opposing second side of the base portion,wherein the adapter bracket defines an open slot configured to receiveand retain a portion of the troffer housing between the first wall andthe second wall thereby facilitating a retrofit installation.
 5. Thesystem of claim 4, wherein the first wall defines a first generallyvertical portion, and wherein the second wall defines a second generallyvertical portion.
 6. The system of claim 4, wherein the second walldefines a lip configured to prevent the adaptor bracket from movinghorizontally in relation to the T-bar, and wherein the lip is in contactwith the troffer housing.
 7. The system of claim 2, wherein the adaptorbracket includes two slots equally spaced from the ends of the adaptorbracket.
 8. The system of claim 2, the adaptor bracket defining a firstadaptor bracket, further comprising a second adaptor bracket, whereinthe first adaptor bracket and the second adaptor bracket are configuredto be placed on separate T-bars on opposite sides of the trofferhousing, and wherein either of the first adaptor bracket and the secondadaptor bracket has slots that receive a pair of hinges of the doorassembly and the other adaptor bracket has slots that receive a pair oflatches of the door assembly.
 9. The system of claim 2, wherein theadaptor bracket includes a hook portion which engages a vertical portionof the T-bar.
 10. The system of claim 2, wherein the light sourceincludes at least one light emitting diode.
 11. The system of claim 2,wherein the door assembly includes at least one of a plate lens and acurved lens.
 12. The system of claim 2, wherein the door assemblyfurther comprises a center lens, a first side lens, and a second sidelens.
 13. The system of claim 1, wherein the base portion is configuredsuch that the base portion contacts the troffer housing of the existingtroffer light fixture along the full length thereof.
 14. An adaptorbracket for retrofitting an existing troffer light fixture, comprising:a base portion configured to rest on a T-bar of a ceiling system, andfurther configured to be located between the T-bar and a troffer housingof the existing troffer light fixture, the troffer housing of theexisting troffer light fixture is supported along a full length thereofby the base portion when the adaptor bracket is disposed between theT-bar and the troffer housing of the existing troffer light fixture,wherein the base portion extends horizontally and along the entirelength of the adaptor bracket; a wall coupled to the base portion; aslot configured to receive a portion of a troffer door assembly; and alatch surface configured to engage with a latch of the troffer doorassembly.
 15. The adaptor bracket of claim 14, wherein the adaptorbracket has a first end and an opposing second end, wherein the baseportion extends horizontally an entire distance between the first endand the opposing second end of the adaptor bracket.
 16. The adaptorbracket of claim 15, wherein the slot is configured to accept either ahinge or the latch of the troffer door assembly.
 17. The adaptor bracketof claim 16, the wall defining a first wall, wherein the first wall iscoupled to a first side of the base portion, the adaptor bracket furthercomprising a second wall coupled to an opposing second side of the baseportion, wherein the first wall and the second wall cooperate to definean open slot configured to receive and retain a portion of the trofferhousing between the first wall and the second wall thereby facilitatinga retrofit installation.
 18. The adaptor bracket of claim 17, whereinthe first wall defines a first generally vertical portion, and whereinthe second wall defines a second generally vertical portion.
 19. Theadaptor bracket of claim 15, wherein the adaptor bracket includes twoslots equally spaced from the ends of the adaptor bracket.
 20. Theadaptor bracket of claim 15, the adaptor bracket defining a firstadaptor bracket, further comprising a second adaptor bracket, whereinthe first adaptor bracket and the second adaptor bracket are configuredto be placed on separate T-bars on opposite sides of the trofferhousing, and wherein either of the first adaptor bracket and the secondadaptor bracket has slots that receive a pair of hinges of the trofferdoor assembly and the other adaptor bracket has slots that receive apair of latches of the troffer door assembly.
 21. The adaptor bracket ofclaim 14, wherein the adaptor bracket is configured such that the T-baris separated from the troffer housing of the existing troffer lightfixture along the entire length of the adaptor bracket when the adaptorbracket is disposed between the T-bar and the troffer housing of theexisting troffer light fixture.
 22. A method for retrofitting anexisting troffer light fixture having a troffer housing using a doorassembly, comprising: installing an adaptor bracket between the trofferhousing of the existing troffer light fixture and a T-bar of a ceilingsystem, the adaptor bracket including a base portion and a wall coupledto the base portion, the troffer housing of the existing troffer lightfixture is supported along a full length thereof by the base portionwhen the adaptor bracket is disposed between the T-bar and the trofferhousing of the existing troffer light fixture, wherein the base portionextends horizontally and along the entire length of the adaptor bracket;removing a door of the existing troffer light fixture; hanging the doorassembly from the adaptor bracket; disconnecting the wiring from a powersource to the existing troffer light fixture; wiring the door assemblyto the wiring from the power source; closing the door assembly; andlatching the door assembly.
 23. The method of claim 22, wherein the baseportion is continuous from a first end of the adaptor bracket to asecond end of the adaptor bracket.